It is known to provide package inserts between layers of articles which are designed not only to cushion the articles with respect to one another but also to wedge or retain the articles in place against shifting. Such inserts, in which the article can be partly nested, are utilized most frequently for fragile articles, e.g. glass bottles, which not only must be held against movement in the respective layers, but cannot be permitted to impact against one another from layer to layer in the stacking of the boxes constituting the packages or in handling if breakage is to be avoided.
Package inserts for these purposes have been provided heretofore as, for example, simple cardboard partitions with essentially the same internal contour as the receptacle or box in which packaging is to be effected. These separators can be relatively rigid to maintain an effective separation of the upper layer from the lower layer and, therefore, effective support of the upper layer of articles.
However, when the articles are of different shapes at their upper and lower ends as is the case with bottles, the cushioning effect is limited and there is always the risk of breakage when packages are stacked or roughly handled.
Furthermore, cardboard separators are very sensitive to moisture and in the case of long-term storage, especially at low temperatures, even where the package is provided in a fluid impermeable envelope or sheath, they are sensitive to moisture formed by condensation and may loose their integrity.
It is known to provide spacers between layers of articles in a package which are composed of thermoformed plastic materials which are molded with shapes corresponding to those of the articles to be seated therein.
These separators have been found to be highly effective in retaining the articles in place, i.e. preventing movement of the articles even if they have different shapes at their upper and lower ends and are also effective cushions between the layers of articles, so that stacking is permitted without danger of breakage, but they have the disadvantage that they cannot be used universally for a variety of different article configurations.
Furthermore, they may not always be biodegradable and thus environmentally sound packaging materials and, of course, are relatively costly because of the material used and the molding operating required, necessitating expensive molds for fabrication as well.